大规模区带离心纯化Vero细胞乙脑疫苗

本文报道一种适合疫苗生产的大规模纯化Ｖｅｒｏ细胞乙脑疫苗的方法。原疫苗经适当浓缩和去除ＤＮＡ处理后,用不连续蔗糖梯度（３６％和６０％）。３２６００ｇ,速率区带离心４ｈ。纯化后疫苗的效力比中国参考疫苗高出６倍以上,补体结合抗原比中国参考疫苗高４～８倍。总蛋白含量低于３０μｇ／ｍＬ,牛血清含量降至０．５μｇ／ｍＬ以下,细胞残余ＤＮＡ低于１００ｐｇ／０．５ｍＬ。用此法连续制备三批纯化疫苗,其纯度和效力均高于日本鼠脑纯化疫苗。此法对于制备其它纯化Ｖｅｒｏ细胞疫苗也具有一定的参考意义。     

Vero细胞乙型脑炎纯化疫苗生产工艺参数的研究

疫苗的生产工艺对保证疫苗的质量起着重要的作用,尤其是对生产过程中一些指标的量化显得更为重要。试验的设计分别考察了细胞接种量,细胞培养时间和离心机纯化样品的蛋白含量等因素对疫苗质量所产生的影响。结果显示,对以上指标的控制的最佳量化是接种量3~7×107/瓶,培养时间6 d,样品蛋白含量2000~2500μg/m l。产品质量稳定。     

Preparation of a purified, inactivated Japanese encephalitis (JE) virus vaccine in Vero cells

An attenuated Japanese encephalitis (JE) virus SA14-14-2 (PDK) was adapted to Vero cells, a continuous cell line that has been licensed for human vaccine production, by serial passages. The resulting virus was purified by tangential flow ultrafiltration followed by sucrose density gradient ultracentrifugation, giving 2.3 mg purified virus per liter of culture supernatant. Treatment with 0.05% formalin for 4 days at 22 °C completely inactivated viral infectivity while preserving its antigenicity. The purified, inactivated JE virus was formulated with alum hydroxide and administered to mice by intraperitoneal route. In terms of its ability to induce anti-JE neutralizing antibody and to protect the immunized animal against neurovirulent virus challenge, the purified, inactivated JE virus formulated with alum was equivalent to the exiting commercial mouse brain-derived vaccine (JE-VAX, Aventis Pasteur Inc.).     

蔗糖梯度离心法纯化Vero细胞乙脑疫苗的纯度分析及与层析法的比较

通过对蔗糖梯度离心法纯化Vero细胞乙脑疫苗的纯化工艺进行分析,发现现行工艺中收取的病毒组分中,不同蔗糖浓度中病毒的纯度是不同的,而呈峰型且与病毒效力峰及蛋白浓度峰不重合。实验结果对今后工艺的改进具有指导意义。另外应用Sephacryl-s-1000凝胶层析法对乙脑病毒进行了纯化研究和分析,发现蔗糖梯度离心法和层析法纯化的病毒的纯度及回收率分别为291．46u／mg、96．01％和309．41 u／mg 65．08％,Sephacryl-s-1000凝胶层析法同样可以获得较高的纯度和收率。     

Development of Vero Cell-Derived Inactivated Japanese Encephalitis Vaccine

We have established a manufacturing system for a Vero cell-derived inactivated Japanese encephalitis vaccine at a 500l scale. The production system involves expansion of Vero cells using microcarrier, followed by virus infection. Except for an additional purification step, the downstream purification processes are similar to those used for the current mouse brain-derived vaccine; cell removal, concentration and removal of low-molecular weight impurities by membrane filtration, formalin-inactivation, sucrose density gradient ultracentrifugation, and Sulfate-Cellulofine column chromatography are conducted. The antigen obtained from the manufacturing system was highly purified and its physico-chemical and immunological properties were comparable with those of antigen derived from mouse brains. Our system is very simple and could be easily scaled-up to allow vaccine production at a several thousand litre scale.     

The morphology of erythroid cells separated by density gradient centrifugation through ficoll

Summary The regenerating blood of geese injected with phenylhydrazine was subjected to large scale, zonal centrifugation through density gradients of Ficoll. In this way, erythroid cells were fractionated according to their respective stages of development. Highly enriched fractions were obtained, containing cells that were well preserved as assessed by both light and electron microscopy. The separated cells exhibited ribosome density and nucleic acid and protein staining patterns typically associated with erythrocyte differentiation. Morphometric analysis of nuclei indicated that despite an apparent net increase in the amount of compact chromatin during development, comparatively little difference existed between the volumes of condensed chromatin present in immature and mature cells. Instead, there was a three fold decrease in nuclear volume between young erythroblasts and reticulocytes, coupled with a concomitant decrease in the volume occupied by dispersed chromatin, RNP and nucleoli. These observations are discussed in relation to molecular changes associated with nuclear differentiation in erythroid cells.Supported by grants from the National Research Council of CanadaWe thank Dr. G. Setterfield for assistance with the EM data and we are grateful to the N.R.C. for use of centrifuges and the zonal rotor     

Large-scale purification of Japanese encephalitis virus from infected mouse brain for preparation of vaccine.

Large volumes of Japanese encephalitis (JE) virus propagated in mouse brain can be easily purified by polyethylene glycol 6,000. By using the polyethylene glycol precipitation method, mouse hemoglobin was almost all separated from the viral suspension, and consequently the total amount of nonviral protein in the viral suspension decreased. The recovery of infectivity was about 100%. The removal of residual polyethylene glycol in the viral suspension was possible without difficulty by means of ethanol precipitation. This method is recommended as an initial step in large-scale purification of Japanese encephalitis virus propagated in mouse brain because it is simple, rapid, and inexpensive.     

柱层析法制备乙型脑炎纯化疫苗的研究

为制备纯化乙型脑炎灭活疫苗,以地鼠肾细胞培养并经灭活的乙型脑炎病毒液,浓缩后上Sepharose 4FF凝胶层析柱,用紫外线280nm波长检测得到三个吸收峰。ELISA法证实第一峰为病毒抗原峰,另两个峰为杂蛋白峰。试验证明Seoharose 4FF凝胶过滤对于提纯乙型脑炎病毒是有效的,能去除99％的杂蛋白。     

Immunogenicity of a recombinant MVA and a DNA vaccine for Japanese encephalitis virus in swine

We previously reported that mice immunized with recombinant modified vaccinia virus Ankara (MVA) encoding Japanese encephalitis virus (JEV) prM and E genes were completely protected against JEV challenge (Nam, J.H., Wyatt, L.S., Chae, S.L., Cho, H.W., Park, Y.K., Moss, B. Vaccine 1999,17: 261-268). In this study, we examined the immunogenicity in swine of this recombinant MVA (vJH9) or a DNA vaccine (pcJH-1) expressing the same JEV genes. Although the booster effect in mice with a combination of vJH9, pcJH-1 and inactivated JEV commercial vaccine was not apparent by measuring JEV antibodies, the recombinant MVA vaccine (vJH9) and the DNA vaccine (pcJH-l) efficiently produced neutralizing antibodies in swine and 2 doses of each showed a booster effect in mice and swine. Therefore, both vJH9 and pcJH-1 are good candidates for a second generation JEV vaccine.     

Vero细胞狂犬病疫苗在凝胶柱层析工艺中样品浓度对纯化效果的影响

为研究浓缩Vero细胞狂犬病疫苗蛋白浓度对纯化效果的影响。用超滤浓缩法对狂犬病疫苗进行不同倍数的超滤浓缩,将浓缩后不同倍数的样品分别用凝胶柱层析法进行纯化,结果样品浓度在40mg/ml以下时,狂犬病毒收集液中杂蛋白去除率可达99%以上,小牛血清含量在25-37.5ng/ml之间;浓缩超过40mg/ml时,并随着样品浓度的增加,狂犬病毒收集液中杂蛋白去除率逐渐下降,且有病毒丢失,因此采用凝胶柱层析法纯化狂犬病疫苗,蛋白浓度应低于40mg/ml。     

Lysis-free separation of hybridoma cells by continuous disc stack centrifugation

The non-destructive removal of hybridoma cells from fermentation broth with an improved disc stack centrifuge (CSA1, Westfalia Separator AG, Oelde, Germany) was investigated. The centrifuge was equipped with a hydrohermetic feed system, which allowed a gentle, shearless acceleration of the cells inside the bowl. No significant cell damage was observed during the separation of hybridoma cells from repeated batch fermentation in 100 liter scale. In the clarified liquid phase there was no increase in Lactate-Dehydrogenase (LDH) activity. Consequently, there was no increased exposure of the product to intracellular components.Due to continuous operation with a periodic and automatic discharge of sediment, a high throughput was achieved without any considerable loss of product. The clarification for mammalian cells was in the range of 99% to 99.9%, depending on the operating conditions. The content of cell debris and other small particles decreased about 30 to 50%, depending on the particle load in the feed stream. The centrifuge was fully contained; cleaning and sterilizing in place possible. Therefore, the decice could be integrated easily into the fermentation process.     

The fractionation of nuclei from mammalian cells by zonal centrifugation

1. Purified liver nuclei from adult rats separate into two main zones when centrifuged in the slow-speed zonal rotor. One zone contains diploid nuclei, the other tetraploid. 2. The effect of age on the pattern of rat liver ploidy was examined. Tetraploid nuclei are virtually absent from young animals. They increase in proportion steadily with age. Partial hepatectomy disturbs the pattern of ploidy. 3. The zonal centrifuge permits the separation of diploid, tetraploid, octaploid and hexadecaploid nuclei from mouse liver. 4. Rat liver nuclei are isopycnic with sucrose solutions of density 1.35 at 5 degrees .     

硫酸鱼精蛋白去除Vero细胞乙脑疫苗残余DNA方法的条件优化

Vero细胞规模化生产疫苗时利用硫酸鱼精蛋白可去除乙型脑炎纯化疫苗中Vero细胞的DNA,实验中对不同条件进行了比较。首先在Vero细胞冻融浓缩液中分别按终浓度2mg/ml、1mg/ml、0.5mg/ml、0.2mg/ml、0.1mg/ml加入鱼精蛋白去除DNA,确定0.2~2mg/ml均有良好去除效果;其次将Vero细胞培养的乙脑病毒浓缩液分3组:第1组按2mg/ml、1mg/ml和0.5mg/ml分别沉淀一次、两次;第2组加入终浓度1mg/ml PS后调pH值为pH6.0、6.4、6.8、7.2、7.6;第3组将NaCl浓度调整至0.029mol/L、0.145mol/L、0.725mol/L,加入终浓度1mg/mlPS。确定低浓度多次沉淀、pH值6.8~7.2、盐浓度0.145mol/L条件下沉淀效果最好。     

Japanese encephalitis virus replicon-based vaccine expressing enterovirus-71 epitope confers dual protection from lethal challenges

Background

To construct safer recombinant flavivirus vaccine, we exploited Japanese encephalitis virus (JEV) replicon-based platform to generate single-round infectious particles (SRIPs) that expressed heterologous neutralizing epitope SP70 derived from enterovirus-71 (EV71). Such pseudo-infectious virus particles, named SRIP-SP70, although are not genuine viable viruses, closely mimic live virus infection to elicit immune responses within one round of viral life cycle.

Results

We found that, besides gaining of full protection to thwart JEV lethal challenge, female outbred ICR mice, when were immunized with SRIP-SP70 by prime-boost protocol, could not only induce SP70-specific and IgG2a predominant antibodies but also provide their newborns certain degree of protection against EV71 lethal challenge.

Conclusions

Our results therefore exemplify that this vaccination strategy could indeed confer an immunized host a dual protective immunity against subsequent lethal challenge from JEV or EV71.     

乙型脑炎SA14-14-2减毒株灭活与不灭活以及P3株死疫苗在小鼠体内的免疫原性比较

将乙型脑炎SA14 14 2减毒株 (简称 14 2株 )病毒液和灭活 14 2株病毒液皮下和腹腔免疫小白鼠 ,P3株死苗作对照 ,测免疫效价 ,结果 14 2株病毒液的效力为 1 8× 10 -5～ 6 .1× 10 -6ID50 /ml,灭活 14 2株病毒液为 9 9× 10 -1～ 7 2× 10 -3 ID50 /ml,P3株死苗为 4 0× 10 -3 ～ 2 2× 10 -4 ID50 /ml。同时免后 14天采血用PRNT法测抗体 ,结果为 14 2株病毒液 1∶2 (皮下和腹腔 ) ;灭活 14 2株病毒液 <1∶2 ,P3株死苗为皮下 1∶2、腹腔 1∶10。结果表明 :14 2株在小白鼠体内的免疫原性远远高于灭活 14 2株病毒液和P3株死疫苗 ,14 2株经灭活后对小白鼠基本无保护作用。 14 2株抗体水平不高 ,而免疫力远高于P3株死苗 ,说明 14 2株与P3株死疫苗免疫性质不同 ,有细胞免疫参与。     

Preparation of neurons and glial cells from rat brain by zonal centrifugation

A method for routine preparation of cell fractions from rat brain is described. A suspension of undamaged cells was obtained by means of a combined enzymatic and mechanical procedure. The cell yield was about 25% of brain DNA.     

The purification of cell nuclei from calf uterus by zonal centrifugation in reorienting density gradients

A method is described for isolation of substantial amounts of pure and enzymatically active nuclei from whole calf uterus. The technique involves a multistep sequential homogenization of the tissue and a zonal centrifugation of the crude nuclear preparation in a reorienting density gradient rotor. Electron and phase contrast microscopic observations show that the nuclei are intact and practically free from cytoplasmic contamination. Based on DNA recovery, the purified fraction contains 9% of the nuclei of the total tissue and more than 19% of the filtered homogenate. The pure nuclear fraction consists of 29% DNA, 7% RNA, and 64% protein, which parallels the composition of purified nuclei from other mammalian tissues.     

人用精制Vero细胞狂犬病疫苗纯化方法选择

人用精制Ｖｅｒｏ细胞狂犬病疫苗为一种安全、有效的新型疫苗,我们在研制该种疫苗时首先比较了密度梯度离心法和凝胶过滤柱层析法,并发现后者最佳。我们选择了以Ｓｅｐｈａｒｏｓｅ ４ＦＦ为介质的凝胶过滤柱层析的工艺,并对该方法的上样量、流速等指标进行了选择,确定了最佳方法,并在研制中使纯化疫苗的杂蛋白去除率达到９９．８％以上,为大规模生产提供了工艺方法。     

An ultra scale‐down analysis of the recovery by dead‐end centrifugation of human cells for therapy

An ultra scale‐down method is described to determine the response of cells to recovery by dead‐end (batch) centrifugation under commercially defined manufacturing conditions. The key variables studied are the cell suspension hold time prior to centrifugation, the relative centrifugal force (RCF), time of centrifugation, cell pellet resuspension velocities, and number of resuspension passes. The cell critical quality attributes studied are the cell membrane integrity and the presence of selected surface markers. Greater hold times and higher RCF values for longer spin times all led to the increased loss of cell membrane integrity. However, this loss was found to occur during intense cell resuspension rather than the preceding centrifugation stage. Controlled resuspension at low stress conditions below a possible critical stress point led to essentially complete cell recovery even at conditions of extreme centrifugation (e.g., RCF of 10000 g for 30 mins) and long (~2 h) holding times before centrifugation. The susceptibility to cell loss during resuspension under conditions of high stress depended on cell type and the age of cells before centrifugation and the level of matrix crosslinking within the cell pellet as determined by the presence of detachment enzymes or possibly the nature of the resuspension medium. Changes in cell surface markers were significant in some cases but to a lower extent than loss of cell membrane integrity. Biotechnol. Bioeng. 2015;112: 997–1011. © 2014 Wiley Periodicals, Inc.